Furnace



June 26, 1928.

R. A. ILG

FURNACE Filed Oct. 28, 1926 2 Sheets-Sheet INVENTOR. PM 6'. 12. BY axawvzz, ,6 rcsmw, ATTORNEYS.

June 26, 1928.

R. A. ILG

FURNACE Filed Oct. 28, 1926 2 Sheets-Sheet Sect/on 4-4- Saar/on 6-6 [5 Seal/on 5-5 INVENTOR. Pain/r4. BY 7 2 6, ,6

*J ATTORNEYS.

" tering with an opening in the rear wall Patented June 26, 1928.

UNITED STATES ROBERT A. ILG, OF CHICAGO, ILLINOIS.

FURNACE.

Application filed October 28, 1926. Serial No. 144,673.

This invention relates to furnaces, having reference more particularly to furnaces of the hot air type used mainly for domestic, church, and school heating.

One object of the invention is to provide an improved furnace of the type mentioned capable of being economically constructed almost entirely from the thinnest sheet steel consistent with necessary strength, Another object is to provide a furnace structure embodying improved means for effecting a thorough heat exchange between the exhaust combustion gases and the incoming air. A further object is to provide in such a furnace, improved means for creating a positive and definite flow of air through the air heating passages of the furnace.

Other objects and attendant advantages of the invention will be apparent to persons skilled in the art as the same becomes better understood by reference to the following detailed description, taken in connection with the accompanying drawings wherein I have illustrated a practical and efiicient embodiment of the principle of the invention, and in which- Fig. 1 is a view, partly in side elevation and partly in vertical section, of my improved furnace;

Fig. 2 is a front elevation of the same;

Fig. 3 is a rear elevation thereof;

Fig. 4 is a vertical longitudinal section taken on the staggered line 4-4 of Fig. 2;

Fig. 5 is a vertical transverse section taken on the line 55 of Fig. 1;

Fig. 6 is a vertical longitudinal section taken on the staggered line 6-6 of Fig. 2.

Referring to the drawings, 10 designates as an entiretya rectangular sheet-metal housing or casing constituting the outer shell of the furnace structure and equipped with a front wall, the upper portion 11 of which may be of sheet steel or cast iron, while the lower portion 12 is preferably constructed J of cast iron to support the fire and draft doors, the operating mechanism of the grate, and the cooling chamber.

Located centrally within and extending lengthwise of the lower portion of the shell or casing 10 is the combustion chamber or tire box 13 of the furnace. This is a relatively narrow long structure, preferably formed with a rounded or dome-shaped top as shown in Fig. 5, with its rear end regis o the housing normally closed by a door '14;

(Fig. On the bottom wall of the combustion chamber are track rails 15 accommodating the wheels of a removable truck 16 on which is mounted a fuel grate 17 of the well-known endless link chain type mounted and supported on front and rear sprocket wheels 19 and 20 respectively. It will be observed, that the grate is not level, as hereto-fore, but is inclined upwardly from its forward to its rear end, the forward end being but a slight distance above the floor of the ash pit, while its rear end is sufficiently elevated to enable the ashes to be discharged into a removable ash can 21 located beneath the rear end of the grate just inside the rear door 14. This provides ample air space below the grate, and at the same time enables the front door 22 of the combustion chamber to be located at a relatively low point in the front wall of the furnace, thus facilitating firing.

Attached to or cast integral with the lower portion 12 of the front wall and surrounding the opening guarded by the door 22 is a hollow casting 23 adapted to contain water; the lower limb of said casting preferably extending inwardly as shown at 23 above the lower front portion of the grate and serving as a battle to prevent the body of coal on the latter from clogging between the front wall and the front end of the grate. Water may be supplied to this jacket through a pipe 24; and, where said jacket is used as a hot water heater, the jacket may be additionally provided with an outflow pipe 25 which, with the pipe 24, may be connected into a suitable water tank. In the event that the water in the jacket 23 is used for lnunidifying the air, the pipe 25 may lead into -one of the heated air passages of the furnace at any convenient point. This water jacket also serves to maintain a relatively low temperature of the front wall of the fire chamber, preventing waste of heat through radiation from the latter. The grate is moved to carry the body of burning coal rcarwardly and upwardly from time to time as fresh firing is required by a simple foot-operated actuate ing mechanism herein shown as comprising a gear wheel 26 fast on the shaft of the lower grate sprocket 19, a pinion 27 meshing with .aid gear wheel and fast on a shaft 28 'ournaled in the side walls of a suitable cas- 1n J 29 mounted on the front wall, a ratchet w reel 30 fast on shaft 28, and a pedal lever 31 carrying a pawl 32 engaged with the till loo

ratchet. 30. The pedal lever 31 is depressed by the loot to actuate the grate. and is rcturncd to normal elevated position by a pull 9? 'ing 23?). At the bottom of the front a cleanoul door ll in whirl is mount ed the usual draft regulator :15.

The furnace it: so con tructcd as to provide a pair of :ynunctrical and relatively long passages for the flow ol' the hot products of comhusltion to the -molte tint: at the top of the furnace. together with a damper-controlled by-pma which may be cmployed to shorten the outllow paasa ge when firing. tip. or when a rapid increaee in heat is desired; and also with a symmetrical pair of relatively long); flow pttflzzrrer for the a r to be heated. said air paasaee'a being 1: arran'. -d that the walls of the filth and ennhe pa; ca will be cfliciently bathed by the all and t llt'tll abstracted therefrom and transmitted to the air.

ithin the outer melt or homing ll) enclosing the major portion ol the top and sides of the tire box lll ia a ;':.-ncrally reetangular inner shcet-metal hoodlilt'e structure comprising a top wall 3t spaced from "l e top all of the housing: It). aide walls 37 parallel with and spaced from the side walls of the housing: and terminating? slightly above the bottom wall of the latter. and a rear wall 38. As best ehown in l igs. i. and 6. the upper portion of this hood is subdivided by suitable partition: to provide draft flue; for the product; of eombuation and also a central vertical line for the outflow of the heated air. il.) (Fig. 5) designnates each of a pair of lon ritudinal partitions. and it) and ll (Fig. (3) a pair of traumverse partitions between the longitudinal partitiona ill). 'lheac partitions, with a portion of the 1 ar wall ltl and the upper portion ll of the trout wall (it the outer casing: together form a central outflow paaaagc or flue for the heated air communicating: with a flue section 42 in the top wall of the casing. to which latter is connected the warm air pipe or pipes lcadin e to thrreeistcr.- \Yhere artificial circulation of the air is employed. an opening is provided in the upper portion of the rear wall ol the outer casing, in which is mounted a trame 43 supporting an electric motor ll operating a direct driven fan -13. which forces the return air into the space between the outer and inner casings. This air floods the space between the top walla of the casings. flows thence down ardly through the spaces between the aide walls. thence upwardly between the side walls; of the inner easing and the side walls of the fire box. and thence upwardly through the warm air flue formed by the partitions 3'5" and 41, the rear wall 38 of the inner casing: and the front wall 11 oi the outer casing.

Between the longitudinal partitions fl?) and extending from the low r edge of the and transverse partition ll) to the rear wall iltl is a hoiizonta' plate it; (l i j. ll): and similarly poaitioned bctween tle lOllfIltlltllfitll partitions l and ex ending l'roni the nppcr edge of the tranaierse partition 41 to the rear wall Zltw is a horizontal plate l7. 'lhcae plates are aperturcd. and litled lieu-wan them is a v horl b '-.'-pas: llne fictlion -lfl. The upper and lower rectangular chambers thus formed tonimunicate through upper and lower ports 50 and Til respectively with loneitudinally extending: side liucl'ormrd bctween the lon; ;itudi1'ial partitions ll) and the side walls ill ol the hood. The bottoma ol' there aide tluea are closed by horizontal platca 513: and the rear bottom and top porlions ol' the sp; cc between Filltl side lluce are closed by a horizontal plate .32 and the central longitudinal portion ol' the top wall Iltl. the former ol' which is apcrtured to receive the upper end of a abort tluc acction iii mounted on and communicating with the combustion chamber 13. while the latter is pcrturcd to rcccive a smoke diet-barge llnc fill. Attached to the rear wall of each oi the aide lin s between the upper and lower ports 5t) and 51 is av longitudinally extending batllc plate 51' that is preferably l'orwardly and downwardly in lined, as shown in Fig. 4: and within the line section is a pivoted damper 58 mounted on an operating rod extendiiw through the front wall ot the l'urnaee. The outer aurl'aees of the side "alts 3T of the hood are prelcrably equipped with heat radiating line tStJ. ()n the trout wall of the outer 'asiag are clcanou doors til normally chain the trout ends of the aide aniolt'e lluca.

'here the l'an I.) is employed to create an artilicial circulation of the air. it may be located. as shown in Fig. 1. within the cold air return line (32 which ordinarily com mnnicatw with a grating in the llooz' oil the room above the l'urnacc. Fltnl] air may be permitted to the extent desired by provid inp; on the side of the line ti: an opening guarded by a pivoted wing valve or damper ($3 whi b may be closed or opened more or less by a rod tll which may extend to the room above. Automatic regulation of thc tcmperatuie may. manifestly. be ellccted by actuating the valve till by a thermostat; said valve thus crvin t not only to admit l ltrll air when desired. but tllht). when thermo statically contiollcd. ax an automatic tem peratnre reg: lator.

The operation and advantaew ol' the dcseribcd l'uruace will it is believed he clcar from the foregoing; description oi its structural features.

The cool air. whether forced in by the fan, or flowing in by gravity. tlows over the top and sides of the inner shcll. below the lower ed 4 ol' the side walls of the latter. thence upwardly between aaid aide walla Hit) lie

tit)

and the sides and top of the fire chamber, and thence upwardly through the relatively large central air tlue. IVith the damper .38 closed, smoke and hot gases of combustion flow from the fire box through the short neck 55, thence through the lower ports 51 into the two side tines below the battles 57, flowing tor 'ardly beneath the latter, thence around their front ends, thence rearwardly through the upper portions of the side fines, thence through the upper ports fit) into the discharge fine 56. The walls Ziti and 37 of the inner shell thus become highly heated through direct contact with the hot gases. and. since thes walls are bathed by the air flowing through the t'urnace. a very etli ient heat exchange is eli'ected.

The use of thin sheet-metal in the greater portion ot the furnace structure lends itself to economy in production and superior efiiciency in heat exchange; and where employed in connection with artificial air circulation, as shown, increa es the rapidity with which the rooms served by the furnace can he brought to a desired temperature.

\Vhile I have herein shown and described one practical and cfiicicnt embodiment of the principle of the invention, it is manitcst that minor details of structure and arrangement may he resorted to without departing from the principle of the invention or sacrificing any of the benefits or advantages thereof. Hence, I do not limit the invention to the exact construction shown and described for purposes of illustration, but reserve all such variations, modifications and mechanical equivalents as fall within the spirit and purview ot the claims.

I claim- 1. In a hot air furnace, the combiliation of an outer casing hav ng a cold air supply open ng in its rear wall. a tire box located in the lower portion ot' said casing. a hood within said outer casing straddling the top and sides or" said tire box with its t p. side and rear walls spaced from the corresponding walls of said outer casing to provide downtlow air passages communicating at th ir lower ends with the interior of said hood. smoke fines extending t'rom said tire box thiough said hood, a warm air discharge tlu extending through the top walls of said outer casing and said hood and commuuics-iting at its lower end with the space. between said hood and tire box, and a fan adapted to force air through the opening in the rear wall of said outer casing.

2. In a hot air furnace, the combination of an outer casing having a cold air supply opening in its rear wall, a fire box located in the lower portion of said casing. a hood within said outer casing straddling the top and sides of said fire box with its top, side and rear walls spaced from the correspond ing walls of said outer casing to provide downfiow air passages communicating at their lower ends with the interior ot said hood. circuitous and direct smoke fines from said fire box formed in said hood, a damper in said direct smoke fine, a warm air discharge tlue extending through said hood and outer casing and communicating at its lower end with the space between said hood and fire box, and a fan adapted to force air through the opening in the rear wall of said outer casing.

3. In a hot air furnace, the combination of a rectangular sheet-metal outer casing having a. cold air supply opening in its rear wall, a tire box located in and extending full length of the lower portion of said casing, a rectangular sheet-metal hood within said outer casing straddling the. top and sides of said fire box with its top, side and rear walls spaced from the corresponding Walls of said outer casing to provide downtlow air passages communicating at their lower ends with the interior of said hood, circuitous and direct smoke flues from said fire box formed in said hood, a damper in said direct smoke flue having an operating rod extending through a wall of said outer casing, a warm air discharge flue extending through said hood and outer casing and communicating at its lower end with the space between said hood and fire box, and a tan mounted in the opening in the rear Wall of said outer casing.

4. In a hot air furnace, the combination of a rectangular sheet-metal outer casing having a cold air supply opening in its rear wall. a fire box located in and extending full length of the lower portion of said casing, a rectangular sheet-metal hood within said outer casing straddling the top and sides of said tire box with its top, sidi and rear walls spaced from the corres 'ionding walls of said outer casing. the lower ends ot' the side walls of said hood terminating above the bottom wall of said outer casing, heat radiating fins on the side walls of said hood, a direct smoke fine from said tire box formed in said hood, circuitous smoke fines formed in said hood on either side of said direct fine and ported to the latter, a damper in said di rect fiue equipped with an operating rod extending through a wall of said outer casing, a warm air discharge flue extending through said hood and outer casing forwardly of said direct smoke fine and between said circuitous fines and C(Hflflllllllt'fltlllg at its lower end with the space between said hood and tire box, and a fan mounted in the opening in the rear wall of said outer casing.

5. In a hot air furnace, the combination of a rectangular sheet-metal outer casing having a cold air supply opening in its rear wall, a fire box located in and extending full length of the lower portion of said casing, a rectangular sheet-metal hood within said outer casing straddling the top and sides of said fire box with its top, side and rear walls spaeed from the corresponding walls of said outer easin; to provide downtlow air passages eonununieating at their lower ends with the interior of said hood, longitudinal and transverse partitions in said hood dividing the latter into a pair of side smoke tlues, a central smoke flue eonununiratin; with said tire box and a central warm air dis-- charge llue located l'orwardl i' of said central smoke flue, said lougitudii'lal partitions formed with upper and lower ports through which said side and Central smoke flues rommunicate, baflle plates in said side lines between said upper and lower ports extending from the rear Walls of said side lines to points near the front- Walls thereof, a damper in said central smoke flue between said upper and lower ports, and a fan mounted in the opening in the rear wall of said outer casing.

ROBERT A. ILG. 

